I removed multiverse and it seems it work, after tons of testing i think i've figured out the problem. When I load in too many worlds the server throws up the annotated error. it's definitely interesting as i don't know how to delete worlds without multiverse.
Edit one - Yup, the problem occured when I load in too many worlds, i think about three. It's probably because i'm losing space to minehut not deleting plugin configs when you remove plugins. I deleted all my warps from file manager and server starts up again. I'll try removing unneeded plugin and config files and will edit again, thanks for all the help
Edit two - Turns out minehut has inbuilt deleting, command is /delete
Edit 2.9 - Trying to install multiverse, mv inventories and mv portals again, lets see if it works.
Edit 2.91 - LETS (Can i swear here?) F**CKING GOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO, Multiverse loaded without any errors, time to try setting up my spawn worlds and stuff. Thanks for the help everyone.
Edit 2.92 - After I loaded in two worlds and tried setting things up, server stopped responding to ingame commands, which is a sign that's its about to die lol oof. Might not work, but i'm still happy that it loaded in Multiverse without issues. The error is back, time to debug.
Edit 3 - Tried reseting multiverse's config, didn't work. Had to remove it, i'll try downloading a RAM Optimisation plugin or something of that kind. Ending - At this point, it seems unreasonable to try working on the server. I'm going to reset it because managing worlds is very important and i think I can implement new things to the server now, Thank you all for helping